34 research outputs found

    Stream-Based Authentication Strategy Using IoT Sensor Data in Multi-homing Sub-aqueous Big Data Network

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    Big data analytics has addressed many in-place and remote network issues in a sub-aqueous distributed computing environment. Recently, a new phenomenon is introduced in the data analytics clusters that focus on multi-homing network connectivity procedures among off-ground multiple nodes of the large-scale on-running wireless industrial applications. In this way, the clusters perform multi-layer cross-connected task processing among various networks simultaneously and perform stream based data block placement over multiple nodes in a sequential order. This satisfies the procedural performance of the cluster; however, security remains an open issue in it because of unavailability of inter-network data block processing authorization. In this paper, we propose a stream based authentication mechanism, that specifically addresses security concerns of multi-homing sub-aqueous big data networks and presents a key authorization infrastructure that performs a proper handing taking among multiple off-ground Datanodes before an inter-network data block exchange. The simulation results depict that our approach increases multi-homing network compatibility and reliability while processing a data block in the sub-aqueous distributed computing environment

    Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review

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    Background: Rigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual participant data. For continuous outcomes, especially those with naturally skewed distributions, summary information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal, we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis. Methods: We undertook two systematic literature reviews to identify methodological approaches used to deal with missing mean or variability summary statistics. Five electronic databases were searched, in addition to the Cochrane Colloquium abstract books and the Cochrane Statistics Methods Group mailing list archive. We also conducted cited reference searching and emailed topic experts to identify recent methodological developments. Details recorded included the description of the method, the information required to implement the method, any underlying assumptions and whether the method could be readily applied in standard statistical software. We provided a summary description of the methods identified, illustrating selected methods in example meta-analysis scenarios. Results: For missing standard deviations (SDs), following screening of 503 articles, fifteen methods were identified in addition to those reported in a previous review. These included Bayesian hierarchical modelling at the meta-analysis level; summary statistic level imputation based on observed SD values from other trials in the meta-analysis; a practical approximation based on the range; and algebraic estimation of the SD based on other summary statistics. Following screening of 1124 articles for methods estimating the mean, one approximate Bayesian computation approach and three papers based on alternative summary statistics were identified. Illustrative meta-analyses showed that when replacing a missing SD the approximation using the range minimised loss of precision and generally performed better than omitting trials. When estimating missing means, a formula using the median, lower quartile and upper quartile performed best in preserving the precision of the meta-analysis findings, although in some scenarios, omitting trials gave superior results. Conclusions: Methods based on summary statistics (minimum, maximum, lower quartile, upper quartile, median) reported in the literature facilitate more comprehensive inclusion of randomised controlled trials with missing mean or variability summary statistics within meta-analyses

    The selective post-translational processing of transcription factor Nrf1 yields distinct isoforms that dictate its ability to differentially regulate gene expression

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    Upon translation, the N-terminal homology box 1 (NHB1) signal anchor sequence of Nrf1 integrates it within the endoplasmic reticulum (ER) whilst its transactivation domains [TADs, including acidic domain 1 (AD1), the flanking Asn/Ser/Thr-rich (NST) domain and AD2] are transiently translocated into the ER lumen, whereupon the NST domain is glycosylated to yield an inactive 120-kDa glycoprotein. Subsequently, these TADs are retrotranslocated into extra-luminal subcellular compartments, where Nrf1 is deglycosylated to yield an active 95-kDa isoform. Herein, we report that AD1 and AD2 are required for the stability of the 120-kDa Nrf1 glycoprotein, but not that of the non-glycosylated/de-glycosylated 95-kDa isoform. Degrons within AD1 do not promote proteolytic degradation of the 120-kDa Nrf1 glycoprotein. However, repositioning of AD2-adjoining degrons (i.e. DSGLS-containing SDS1 and PEST2 sequences) into the cyto/nucleoplasm enables selective topovectorial processing of Nrf1 by the proteasome and/or calpains to generate a cleaved active 85-kDa Nrf1 or a dominant-negative 36-kDa Nrf1γ. Production of Nrf1γ is abolished by removal of SDS1 or PEST2 degrons, whereas production of the cleaved 85-kDa Nrf1 is blocked by deletion of the ER luminal-anchoring NHB2 sequence (aa 81–106). Importantly, Nrf1 activity is positively and/or negatively regulated by distinct doses of proteasome and calpain inhibitors

    Update on hypertrophic cardiomyopathy and a guide to the guidelines

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    Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiovascular disorder, affecting 1 in 500 individuals worldwide. Existing epidemiological studies might have underestimated the prevalence of HCM, however, owing to limited inclusion of individuals with early, incomplete phenotypic expression. Clinical manifestations of HCM include diastolic dysfunction, left ventricular outflow tract obstruction, ischaemia, atrial fibrillation, abnormal vascular responses and, in 5% of patients, progression to a 'burnt-out' phase characterized by systolic impairment. Disease-related mortality is most often attributable to sudden cardiac death, heart failure, and embolic stroke. The majority of individuals with HCM, however, have normal or near-normal life expectancy, owing in part to contemporary management strategies including family screening, risk stratification, thromboembolic prophylaxis, and implantation of cardioverter-defibrillators. The clinical guidelines for HCM issued by the ACC Foundation/AHA and the ESC facilitate evaluation and management of the disease. In this Review, we aim to assist clinicians in navigating the guidelines by highlighting important updates, current gaps in knowledge, differences in the recommendations, and challenges in implementing them, including aids and pitfalls in clinical and pathological evaluation. We also discuss the advances in genetics, imaging, and molecular research that will underpin future developments in diagnosis and therapy for HCM

    Ultra‑high resolution X‑ray structures of two forms of human recombinant insulin at 100 K

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    The crystal structure of a commercially available form of human recombinant (HR) insulin, Insugen (I), used in the treatment of diabetes has been determined to 0.92 Å resolution using low temperature, 100 K, synchrotron X-ray data collected at 16,000 keV (λ = 0.77 Å). Refinement carried out with anisotropic displacement parameters, removal of main-chain stereochemical restraints, inclusion of H atoms in calculated positions, and 220 water molecules, converged to a final value of R = 0.1112 and Rfree = 0.1466. The structure includes what is thought to be an ordered propanol molecule (POL) only in chain D(4) and a solvated acetate molecule (ACT) coordinated to the Zn atom only in chain B(2). Possible origins and consequences of the propanol and acetate molecules are discussed. Three types of amino acid representation in the electron density are examined in detail: (i) sharp with very clearly resolved features; (ii) well resolved but clearly divided into two conformations which are well behaved in the refinement, both having high quality geometry; (iii) poor density and difficult or impossible to model. An example of type (ii) is observed for the intra-chain disulphide bridge in chain C(3) between SÎł6–SÎł11 which has two clear conformations with relative refined occupancies of 0.8 and 0.2, respectively. In contrast the corresponding S–S bridge in chain A(1) shows one clearly defined conformation. A molecular dynamics study has provided a rational explanation of this difference between chains A and C. More generally, differences in the electron density features between corresponding residues in chains A and C and chains B and D is a common observation in the Insugen (I) structure and these effects are discussed in detail. The crystal structure, also at 0.92 Å and 100 K, of a second commercially available form of human recombinant insulin, Intergen (II), deposited in the Protein Data Bank as 3W7Y which remains otherwise unpublished is compared here with the Insugen (I) structure. In the Intergen (II) structure there is no solvated propanol or acetate molecule. The electron density of Intergen (II), however, does also exhibit the three types of amino acid representations as in Insugen (I). These effects do not necessarily correspond between chains A and C or chains B and D in Intergen (II), or between corresponding residues in Insugen (I). The results of this comparison are reported

    Frequency of genetic variants associated with arrhythmogenic right ventricular cardiomyopathy in the genome aggregation database

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    Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited heart-muscle disorder, which is the most common cause of life-threatening arrhythmias and sudden cardiac death (SCD) in young adults and athletes. Early and accurate diagnosis can be crucial in effective ARVC management and prevention of SCD. The genome Aggregation Database (gnomAD) population of 138,632 unrelated individuals was searched for previously identified ARVC variants, classified as pathogenic or unknown on the disease genetic variant database (http://www.arvcdatabase.info/), in five most-commonly mutated genes: PKP2, DSP, DSG2, DSC2 and JUP, where variants account for 40-50% of all the ARVC cases. Minor allele frequency (MAF) of 0.001 was used to define variants as rare or common. The gnomAD data contained 117/364 (32%) of the previously reported pathogenic and 152/266 (57%) of the unknown ARVC variants. The cross-ethnic analysis of MAF revealed that 11 previously classified pathogenic and 57 unknown variants were common (MAF ≄ 0.001) in at least one ethnic gnomAD population and therefore unlikely to be ARVC causing. After applying our MAF analysis the overall frequency of pathogenic ARVC variants in gnomAD was one in 257 individuals, but a more stringent cut-off (MAF ≄ 0.0001) gave a frequency of one in 845, closer to the estimated phenotypic frequency of the disease. Our study demonstrates that the analysis of large cross-ethnic population sequencing data can significantly improve disease variant interpretation. Higher than expected frequency of ARVC variants suggests that a proportion of ARVC-causing variants may be inaccurately classified, implying reduced penetrance of some variants, and/or a polygenic aetiology of ARVC

    Refined crystal structure and absolute configuration of the di-amino acid peptide cyclo(L-aspartyl-L-aspartyl): comparison with the DFT calculated structure

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    The X-ray crystal structure of the di-amino acid peptide cyclo(l-Asp-l-Asp), C6H10N2O4, has been re-determined at 20 °C using CuKα radiation, λ = 1.54180 Å. The crystals are triclinic P1 with unit cell dimensions a = 5.0829(3), b = 5.0285(4), c = 18.8765(10) Å, α = 88.95(2)°, ÎČ = 83.72(2)°, Îł = 74.79(2)°, unit cell volume 462.75(5) Å3, and Z = 2 independent molecules A and B per asymmetric unit. Final R indices [I > 2sigma(I)] are R1 = 0.0492, wR2 = 0.1039 for 2,540 independent reflections; R1 = 0.0686 and wR2 = 0.1112 for all 3,193 data; Goodness of Fit, S = 0.979, and the Flack x parameter = 0.1(3). In both molecules the overall shape of the diketopiperazine (DKP) ring displays an almost identical slightly distorted boat conformation with pseudo symmetry C2v (mm2). The two side chains of the cyclic peptide on opposite sides of both molecules differ in their conformations, one side being extended and the other coiled. The coiled chains are located away from the DKP ring plane while the extended chains lie approximately parallel to it. The crystal packing employs two strong hydrogen bonds, which traverse the entire crystal via translational repeats. The geometry of cyclo(l-Asp-l-Asp) derived from Ab initio calculations is compared with those of molecules A and B derived from the X-ray structure reported here. In this calculated model the DKP ring is in a pseudo twist boat conformation; both side chains are extended and lie approximately parallel to the DKP ring face as opposed to molecules A and B in the X-ray structure in each of which one side chain is approximately parallel and the other is folded away from the DKP ring face. Graphical Abstract Cyclic di-amino acid peptides are amongst the “simplest” peptide derivatives commonly found in nature and continue to be of long-standing interdisciplinary scientific interest with respect to potential pharmaceutical applications. Cyclo(l-Asp-l-Asp) is an example of a cyclic di-amino acid peptide, which has a six membered ring, and the amide linkage adopts a cis conformation. In contrast linear (l-Asp-l-Asp) is zwitterionic and has a single amide function which adopts the trans conformation. The synthesis and an X-ray structure of cyclo(l-Asp-l-Asp) have previously been reported, the latter being assigned the wrong absolute configuration. For the purposes of the present study, requiring precise molecular geometry, it was decided to carry out a re-determination of the crystal structure using a more complete measured set of independent intensities (94% against 36%) and correspondingly improved data/parameter ratio (3193/326 against 1215/369)
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